A driveway or pavement sealer product is usually a water based asphalt product that is applied in a liquid form over an existing road surface as a coating. As a water based product, it requires temperatures above 65 F to cure properly. If temperatures fall below 65 F, curing time may increase and/or curing may not be complete. In order to expand the possible application conditions given environmental conditions during application, there is a desire to make a water-based pavement sealer product having decreased drying/curing time and/or able to cure at lower temperatures.
Known driveway sealers have been made using aqueous drilling fluid. Drilling fluid has typically consisted of bentonite clay, with an acrylic polymer as a thickener. Drilling fluid slurry products have been available with a clay, such as a bentonite using a polymer, already incorporated in the slurry, to control viscosity in making driveway sealer products. However, water-based pavement sealer products have been known to exhibit low wear resistance properties. As such, there is a desire to make a water-based pavement sealer having increased wear resistance.
One idea for increasing wear resistance properties is to add an aggregate, such as sand or limestone, to result in a product having a harder surface.
Aside from driveway/pavement sealer asphalt products, the use of limestone or treated limestone added as a slurry, and then added to asphalt or asphalt emulsion, has been known for cold paving applications. For example, an asphalt emulsion pavement product is known, having asphalt and clay that includes limestone as a filler that may be post-added as a dry powder to the emulsion. For example, an aqueous cold paving formulation including powder lime and aggregate that is wetted (mixed with water), with an asphalt emulsion then added to the aqueous mixture, is known. According to one such cold paving formulation using asphalt emulsion, aggregates may be mixed with Portland cement or lime, water and then added to an asphalt emulsion. Alkali metal salts, metal hydroxides, ammonium salts and ammonium hydroxide are used to control breaking of the emulsion. However, this cold paving application is a micro-paving product and not a coating product.
Accordingly, there exists a need in the art for an asphalt driveway/pavement sealer product and method of making it, which provides a water-based product having increased wear resistance and shorter drying time at low temperatures that has a desired deeper black color.